 /*******************************************************************************
  * Copyright (c) 2000, 2006 IBM Corporation and others.
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v1.0
  * which accompanies this distribution, and is available at
  * http://www.eclipse.org/legal/epl-v10.html
  *
  * Contributors:
  * IBM Corporation - initial API and implementation
  *******************************************************************************/
 package org.eclipse.core.internal.registry;

 import java.util.Arrays ;
 import java.util.Map ;
 import org.eclipse.core.runtime.IExtensionDelta;
 import org.eclipse.core.runtime.IRegistryChangeEvent;

 /**
  * A registry change event implementation. A filter can be specified. In that case, only
  * deltas for the selected host will be available to clients.
  */
 public final class RegistryChangeEvent implements IRegistryChangeEvent {
     private String filter;
     private Map deltas;

     public RegistryChangeEvent(Map deltas, String filter) {
         this.deltas = deltas;
         this.filter = filter;
     }

     private RegistryDelta[] getHostDeltas() {
         // if there is a filter, return only the delta for the selected plug-in
 if (filter != null) {
             RegistryDelta singleDelta = getHostDelta(filter);
             return singleDelta == null ? new RegistryDelta[0] : new RegistryDelta[] {singleDelta};
         }
         // there is no filter - return all deltas
 return (RegistryDelta[]) deltas.values().toArray(new RegistryDelta[deltas.size()]);
     }

     private RegistryDelta getHostDelta(String pluginId) {
         if (filter != null && !pluginId.equals(filter))
             return null;
         return (RegistryDelta) deltas.get(pluginId);
     }

     public IExtensionDelta[] getExtensionDeltas() {
         RegistryDelta[] hostDeltas = getHostDeltas();
         if (hostDeltas.length == 0)
             return new IExtensionDelta[0];
         int extensionDeltasSize = 0;
         for (int i = 0; i < hostDeltas.length; i++)
             extensionDeltasSize += hostDeltas[i].getExtensionDeltasCount();
         IExtensionDelta[] extensionDeltas = new IExtensionDelta[extensionDeltasSize];
         for (int i = 0, offset = 0; i < hostDeltas.length; i++) {
             IExtensionDelta[] hostExtDeltas = hostDeltas[i].getExtensionDeltas();
             System.arraycopy(hostExtDeltas, 0, extensionDeltas, offset, hostExtDeltas.length);
             offset += hostExtDeltas.length;
         }
         return extensionDeltas;
     }

     public IExtensionDelta[] getExtensionDeltas(String hostName) {
         RegistryDelta hostDelta = getHostDelta(hostName);
         if (hostDelta == null)
             return new IExtensionDelta[0];
         return hostDelta.getExtensionDeltas();
     }

     public IExtensionDelta[] getExtensionDeltas(String hostName, String extensionPoint) {
         RegistryDelta hostDelta = getHostDelta(hostName);
         if (hostDelta == null)
             return new IExtensionDelta[0];
         return hostDelta.getExtensionDeltas(hostName + '.' + extensionPoint);
     }

     public IExtensionDelta getExtensionDelta(String hostName, String extensionPoint, String extension) {
         RegistryDelta hostDelta = getHostDelta(hostName);
         if (hostDelta == null)
             return null;
         return hostDelta.getExtensionDelta(hostName + '.' + extensionPoint, extension);
     }

     public String toString() {
         return "RegistryChangeEvent: " + Arrays.asList(getHostDeltas()); //$NON-NLS-1$
 }
 }

